Embodiments of disclosed technology relate to a color filter substrate and a liquid crystal display.
Liquid Crystal Displays (LCDs) have high display quality, small volume, low driving voltage, low power consumption, little damage to human eyes, etc., so are mainly employed for the flat panel display devices of personal computers and notebook computers, and have been developed rapidly in the market. A color filter substrate having red, green, and blue primary colorful filter blocks is used for a full-color liquid crystal display. The orientation state of liquid crystal molecules is controlled by changing a driving voltage from a driving integrated chip (IC), and the liquid crystal layer can work as a switch for electing to let light from a backlight module pass through or not. Different colors are formed by adjusting ratio among the three primary colors, so that various colors can be created, and the liquid crystal displays can present sharp, living, and colorful images. Therefore, the color filter substrate is a key component in a liquid crystal display.
At present, a pigment dispersion method is a mainstream method for manufacturing a color filter substrate. In this method, a light blocking matrix (black matrix) for blocking light is firstly formed on a transparent glass substrate, color filter layers of red (R), green (G), and blue (B) primary colors are then sequentially formed. The positions of red, green, and blue colors must be aligned with the sub-pixels on a thin film transistor array substrate which is opposite to the color filter substrate after assembly. Pigment materials for forming the red, green, and blue colorful filter blocks are expensive, and the red, green, and blue colorful filter blocks are formed by a plurality of mask processes, and the processes are repeated with respect to each color. Thus, production efficiency is reduced, and production cost is increased.
Since the pigment dispersion method renders complicate processes and high cost, an ink jet method for forming color filter substrate is gradually developed, in which red (R), green (G), and blue (B) ink tiny drops are sprayed on regions corresponding to sub-pixels on a substrate so as to form sub-pixels. The corresponding sub-pixels respectively transmit red, green, and blue primary color light and block light of the other colors. Ink jet devices simultaneously spray R, G, and B color ink drops on the substrate to form RGB color layers in one step. Thus, the ink jet method for forming the color filter substrate can save the cost and simplify production processes, and the high cost for performing mask processes can also be omitted. For preventing the leakage of light and the mixing of RGB color inks, a dividing wall is usually used for isolating the sub-pixel regions. The black dividing walls (black matrix) can be directly formed on the substrate for the isolation of the sub-pixel regions.
While the method for manufacturing the color filter substrate is further improved, the type of the color filter substrate is also gradually developed. An RGBW color filter substrate (also referred to as “white+color filter substrate”) is formed by disposing transparent white colorful filter blocks, i.e., white (W) region, among the RGB colorful filter blocks, so that more light from the backlight module can be pass through and thus the brightness of the image displayed by the liquid crystal panel can be enhanced.
The conventional RGBW color filter substrate has an arrangement of color regions as shown in FIG. 1A or 1B, in which one pixel consists of four sub-pixels, and each sub-pixel corresponds to one of RGBW colors and has the same area as the others. FIG. 1A shows that one pixel consists of four sub-pixels in parallel in the order of RGBW; and FIG. 1B shows that one pixel consists of four sub-pixels in a square arrangement with each color filter occupy one corner. With the arrangement as shown in FIG. 1A, W region is adjoining one of the R, G, and B regions, or when W region is not located at the edge of the pixel regions, it is adjoining two of the R, G, and B regions, thus there is at least one color (e.g., G in FIG. 1A) can not be adjoining W region, so that color mixing is prone to non-uniform. With the arrangement as shown in FIG. 1B, the arrangement of W region with respect to each of the R, G, and B regions is also different, which also cause the non-uniform of the color mixing.